Finding the Fourth Proportional to 2,145.83, 3,216.65 and 913.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.83 : 3,216.65 = 913.55 : x
2. Step 2: Convert to fraction form
   2,145.83/3,216.65 = 913.55/x
3. Step 3: Cross multiply
   2,145.83x = 3,216.65 × 913.55
4. Step 4: Simplify right side
   2,145.83x = 2,938,549.96
5. Step 5: Solve for x
   x = 2,938,549.96/2,145.83
6. Step 6: Final answer
   x = 1,369.43